Article Figures & Data
Figures
- Figure 1.
Experimental protocol. While participants performed a visual search (finding a T letter among L’s), they were stimulated over the right-FEF or the Vertex (control) with a double-pulse of TMS (25 ms interval) applied at random delays between 50 and 450 ms (50 ms increments) after the search array onset.
- Figure 2.
TMS modulates attentional search periodically. A, D′ modulations (test–control condition) are represented as a function of TMS latencies from the search array onset. The color lines represent each individual study [yellow, current FEF study; blue, first V1 study (Dugué et al., 2011); red, second V1 study (Dugué et al., 2015a)]. The black line is the average across all three studies. B, Amplitude spectrum obtained by FFT decomposition of the averaged data across the three studies. The red shaded area represents the significant spectral components and the *peak at 6.3 Hz (p < 0.05). C, E, G, represent criterion, hit rates, and false-alarm rates modulations, respectively (same representation as in A). D, F, H, represent their corresponding amplitude spectra. The red shaded area represents the significant spectral components and the *peaks at 6 Hz and 18 Hz for criterion and 5.8 Hz for hit rates (p < 0.05).
- Figure 3.
Attentional periodicity in V1 and FEF. For each study, the graphs in the left column represent the amplitude spectra obtained by FFT decomposition of the averaged performance (as per hit rates modulation; see Materials and Methods) across participants. Note the distinct frequency axis in the middle, because of the increased time resolution (and corresponding Nyquist frequency) in that study. The bottom, dashed black line represents the amplitude spectrum of the surrogate distribution. The red shaded area represents the significant spectral components and the *peaks at 6 Hz and 18 Hz for the second V1 study and 6.5 Hz for the FEF study (p < 0.05). The right column represents the phase distribution of the peak frequency across participants. P values are obtained from Rayleigh test for non-uniform distribution of circular data.
Tables
- Table 1.
TMS studies investigating the role of attention during difficult, visual search tasks
Stimulation parameters Study Behavioral manipulation Test region Control Type of stimulation Stimulation intensity n Conclusions Ashbridge (1997) Feature: color
Conjunction:
color-orientationR-PC No-TMS Single-pulse at 11 possible delays (from 0 to 200 ms) 80% MSI 5 R-PC involved in conjunction but not feature tasks Walsh et al. (1998) Conjunction:
color-orientationR-PC No-TMS Single-pulse at 11 possible delays (from 0 to 200 ms) 80% MSI 3 R-PC involved in novel but not learned conjunction tasks Juan and Walsh (2003) Feature: color
Conjunction:
color-orientationV1/V2 No-TMS 10 Hz for 500 ms and
Double-pulse (40 or 100 ms interval) at 6 possible delays65% MSI 8, 6, & 6 V1 involved at late delays (feedback) during conjunction but not feature tasks Muggleton et al. (2003) Feature: color
Conjunction:
color-orientationR-FEF
L-FEFVertex
V510 Hz for 500 ms 65% MSI 5 FEF is involved in visual selection, in the absence of saccade Ellison et al. (2004) Feature: orientation
Conjunction:
color-orientationR-PPC
R-STGSHAM on R-PPC or R-STG R-PPC: 10 Hz for 500 ms
R-STG: 4 Hz for 500 ms65% MSI 5 R-PPC involved in conjunction and R-STG in feature O’Shea et al. (2004) Conjunction:
color-orientationR-FEF Vertex
V5Double-pulse (40 ms interval) at 5 possible delays (from 0 to 120 ms), 40 ms before mask onset FEF & Vertex: 65% MSI
V5: 110% phosphene threshold12 FEF is involved in visual discrimination, in the absence of saccade Fuggetta et al. (2006) Conjunction:
color-orientationR-PPC Vertex Single-pulse 100 ms after stimulus onset 85% MSI on average 7 R-PPC involved in conjunction task Ellison et al. (2007) Conjunction:
color-orientation and
motion-orientationR-PPC
R-V5SHAM on R-PPC or
R-V510 Hz for 500 ms 65% MSI 7 R-PPC involved in color-orientation
R-V5 in motion-orientationKalla et al. (2008) Conjunction:
color-orientationR-FEF
R-PPCNo-TMS Double-pulse (40 ms interval) at 5 possible delays (from 0 to 200 ms) 60% MSI 9 R-FEF involved earlier than R-PPC in conjunction tasks Muggleton et al. (2008) Feature: color
Conjunction:
color-orientationR-AG
L-AGVertex
No-TMS10 Hz for 500 ms 65% MSI 8 R-AG but not L-AG involved in conjunction but not feature tasks Schindler et al. (2008) Feature: orientation
Conjunction:
color-orientationR-PPC
R-STGSHAM on R-PPC or R-STG R-PPC: 10 Hz for 500 ms
R-STG: 4 Hz for 500 ms65% MSI 5 R-STG processes the left part of the search array presented contralateral
R-PPC involved for left visual field when full-fields arrayKalla et al. (2009) Feature: color
Conjunction:
color-orientationDLPFC Vertex
V5TBS: 50 Hz bursts at 5 Hz 40% MSI 12 DLPCF involved in conjunction but not feature tasks Dugué et al. (2011) Conjunction:
L vs T and L vs +V1/V2 Stimulus at non-retinotopic location Double-pulse (25 ms interval) at 8 possible delays (from 100 to 450 ms) 55% MSI 11 V1 involved at late delays (feedback) during conjunction but not feature tasks Lane et al. (2011) Feature:
shape
Conjunction:
color-orientationR-PPC SHAM on R-PPC 10 Hz for 500 ms 65% MSI 12 R-PPC involved in conjunction and feature tasks when participants have to point to the target, but only conjunction when button press response Muggleton et al. (2011) Conjunction:
color-orientationR-FEF
L-PPCNo-TMS 10 Hz for 500 ms 60% MSI 8 L-PPC involved when manual motor response required Dugué et al. (2015a) Conjunction:
L vs T and L vs +V1/V2 Stimulus at non-retinotopic location Double-pulse: one at 312.5 ms and one 13 possible delays (from 112.5 to 437.5 ms) 55% MSI 10 V1 involved periodically during conjunction but not feature tasks (∼6 Hz) Yan et al. (2016) Feature:
color
Conjunction:
orientation of trianglesR-DLPFC
R-PPCVertex on another group of participants Double-pulse (100 ms interval) 200 ms before search array onset 51% MSI on average 16 DLPFC is involved in the conjunction search, while the PPC is involved in the feature search Present study Conjunction:
L vs TR-FEF Vertex Double-pulse (25 ms interval) at 9 possible delays (from 50 to 450 ms) 52% MSI on average 21 FEF involved periodically during a conjunction task (∼6 Hz) For each study we report the behavioral manipulation, the stimulation parameters: tested region (R, Right; L, Left; V5, MT area; PC, parietal cortex; PPC, posterior parietal cortex; AG, angular gyrus, part of the PPC; STG, superior temporal gyrus; DLPFC, dorsolateral prefrontal cortex, right hemisphere), control condition, type of stimulation (TBS, theta burst stimulation; note: otherwise mentioned, the reference is the onset of the visual stimuli) and the intensity of the stimulation (MSI, maximum output stimulation intensity of the TMS machine), the amount of participants for which data were analyzed (n), and finally, the authors’ conclusions.
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